Does LEC usally provide a CSU?

I've seen it both ways. In what kind of application?

Take care, Rich

God bless the USA

No, its typically up to the customer.

Most gear has built in CSU/DSU now-a-days. (data or voice).

WHAT COUNTRY??

In the U.S. the ILEC no longer provides _any_ CPE gear. CLEC's may.

Thanks. We're using Global Crossing as our IXC. They interface with our LEC (ILEC) AT&T. The application is voice/PBX. Currently, our smartjacks are in our server room with a ~7ft ethernet cable going directly to our PBX (no CSU in the middle). It's a very short distance and as far as I'm reading, somewhat abnormal in the fact that the smartjack is in the same room as the PBX. We've been having chronic d-channel failures in the past few months (4 times so far, length of outage varies, on both PRIs, none of which happened before we moved from XO Communications to Global Crossing). No one can figure out what is causing the problem.

In any case, I was just making a case to add a couple CSU's to the budget (it may or may not fix the problem mentioned above). As far as I see, they may not be necessary, but it's somewhat highly recommended. Similar to placing a UPS in between your server and the wall for power conditioning.

Thanks. That definitely helps.

Sorry. I keep forgetting that other countries exist. Typical USA mindset ;-). Thanks for your input. I think you hit the nail on the head, as you seem confident in your answer. We're dealing with an IXC, and they deal with the ILEC. I was hoping to somehow get a couple CSUs for free from the ILEC. Looks like I'll be shelling out for them myself!

Sorry for yelling, but for the question you asked, the 'country' is ritial. In most of the rest of the world, the telco _does_ supply the CSU, or maybe the CSU/DSU combo, and you _have_ to use what they provide.

A stand-alone CSU will be _very_ hard to find. A combination CSU/DSU is considerably more common.

Whether or not you 'need' one, or even "can use one" depends on the interface available on the equipment you're going to hook up to it.

Virtually all modern telephony gear has the CSU/DSU functionality built in.

you_cannot_ just add an outboard unit 'in series' with the built in one.

Another aspect of the CSU is if there is a large distance between the smart jack and the equipment some CSU's can provide a degree of amplification. Similarly if the signal is too hot a CSU can be set to attenuate it.

Take care, Rich

God bless the USA

Not very hard. Adtran CSU ACE series. Very current devices.

Designed to be inserted ahead of another T1 interface to introduce a test interface (if the other gear doesn't provide one), possibly reduce jitter, and provide a more solid signal if needed.

But, most T1 interfaces on CPE gear itself are pretty capable as it is, most gear will let you pull ANSI PMs, but if it doesn't then the Adtran unit will step in and fulfill those functions.

This is more insurance as the OP follows up with. $400 for a "t1 line conditioner" that might fry from a zap vs. $x thousands for an interface card for such-and-such gear might be cheap insurance.

But I don't think for a 7' run from the smartjack to the CPE, its going to do a whole lot.